1. Field of the Invention
The invention generally relates to a bootup and shutdown method of a computer system, and more particularly, to a bootup and shutdown method which can shorten bootup time and a computer system using the same.
2. Description of Related Art
Based on statistics, computer systems have been broadly used, and people have been getting more and more used to work, communicate, browse information, and enjoy their leisure time by using computer systems.
Generally speaking, after a user presses down the power switch of a computer system, the computer system has to go through a series of hardware initialization operations to be successfully started, wherein the basic input/output system (BIOS) plays a very important role. To be specific, after a computer system is powered on, its BIOS is loaded into the memory and executes a power on self test (POST) to initialize and test various hardware components of the computer system, so as to ensure that these hardware components can work properly. The POST includes initializing the central processing unit (CPU) of the computer system to check whether the flags and registers of the CPU are normal. The POST also includes checking the functions of the southbridge and the northbridge, detecting the memory and performing related settings, and initializing various peripheral devices (for example, keyboard, mouse, I/O ports, and sensors). After the POST is completed, a boot device is selected according to the boot order appointed by the user, and the operating system (OS) is then loaded to complete the entire boot process of the computer system.
Based on the advanced configuration and power interface (ACPI) specification, a typical shutdown process turns off all the devices (including the power supply). In this case, the computer system enters into a shutdown mode (e.g. ACPI S5 mode). When next time the computer system is to be booted up, the computer system needs to go through the entire boot process described above, which is very time consuming. Thereby, how to boot up a computer system quickly has become one of the major subjects in the industry.